Abstract: A wall mounted speaker system which is arranged to alleviate problems of unwanted noise in the production and transmission of audio waves, particularly in the lower wave lengths from 20 to 200 hz. There is a speaker unit having a pair of vertically spaced speakers, and an inertial noise suppressing section positioned between the two speakers. The inertial noise suppressing section has an inertial mass which is moved in a back and forth motion to create an inertial offsetting force into a housing structure of the speaker section. The two speakers also create inertial forces which are also transmitted into the housing of the speaker unit, and these are substantially diminished by the interaction of the inertial forces of the speakers and those of the inertial noise suppressing system.

Abstract: A subwoofer cabinet having a volume less than 1 ft3; axially aligned openings in opposed cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular 225 oz. magnet affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and attached at its periphery to the first cage; a flexible spider secured to the former and at its outer periphery to the first cage; a drive amplifier capable of delivering 2,700 watts to a nominal 4 ohm resistive load and swinging 104 volts for delivering (+)&Dgr;v and (−)&Dgr;v drive signals to the voice coil for driving the voice coil driven driver through a peak-to-peak stroke of about 2.

Abstract: An effective insect trap comprises a housing that substantially encloses an interior space for trapping and killing insects. A conduit is attached to or formed from the housing, where the conduit is shaped to facilitate entry of insects into the trap interior space, based on the insects' natural motion and its attraction to light radiating from within the trap. The conduit, or preferably multiple conduits, narrows in cross sectional area to a conduit end that is open to the interior space. A socket used to secure a light bulb is positioned such that, when the bulb is in the socket, the bulb is within about one inch of the conduit end. Overall, the trap hinders the escape of trapped insects through the conduit and under some conditions is selective to biting insects, such as mosquitoes, mosquito types, and sub-miniature biting midges, over other types of insects.

Abstract: A subwoofer cabinet having a volume less that 1 ft3 axially aligned openings in opposed cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular 225 oz. magnet affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and attached at its periphery to the first cage; a flexible spider secured to the former and at its outer periphery to the first cage; a mass driven driver including a 1.7 lb. mass; a second flexible surround secured to the mass and to the second cage; a flexible spider attached to the second cage and to the mass; both surrounds having a uniform thickness of at least 0.1″, an edgeroll having a diameter of at least 1.

Abstract: An audio amplifier comprising a power amplifier section, a power supply, and a control circuit. The power supply is made up of a positive and negative power supply section, with the positive supply section and the negative supply section delivering, respectively, positive and negative power inputs through the power amplifier section. Each power supply section comprises a transformer and a switch section to supply current pulses to the primary winding of the transformer. A filter circuit component is connected to an output of each secondary winding. The control circuit controls the strength of the current pulses of the power supply sections in accordance with the strength of the audio signal.

Abstract: Disclosed is a compact speaker system in which each speaker unit includes a folded ribbon loudspeaker that is mounted on the forward face of the speaker unit housing. Mounted on each side of the speaker housing is a woofer with the region in which the woofers are mounted being sealed and of relatively small volume. Each woofer is constructed to allow relatively long voice coil excursion and hence, high sound output levels. In addition, the woofers are constructed to withstand box pressure substantially greater than 0.2 lbs/in2 that is created that is created within the sealed portion of the speaker housing when the woofers are being driven at high output levels. Signal processing circuitry is included for processing each channel of multi-channel audio programming such as surround sound. The signal processing arrangements of the invention include circuit stages to control channel gain over the low frequency range, the mid-frequency range and the high frequency range.

Abstract: A woofer apparatus having a cabinet defining a chamber, a magnet, a voice coil member positioned to reciprocate in the magnetic field of the magnet, a speaker diaphragm, and a passive radiator diaphragm. The components are arranged so that the maximum box pressure during maximum displacement mode of operation is greater than 0.2 psi. the tuned frequency of the apparatus is, in a preferred mode, at about 35 Hz, so that the passive radiator has substantially greater maximum excursion strokes at maximum displacement than the speaker diaphragm.

Abstract: An audio amplifier having an amplifier section and a power supply. The power supply comprises a positive power supply section and a negative power supply section, each of which provides voltage to the positive and negative power inputs to the amplifier. The control circuitry for the power supply sections causes the voltage output from the power supply sections to vary in accordance with the amplitude of the audio signal so that the power supply voltages track the positive and negative components of the audio signal so that the supply voltages are at a predetermined level above and below the positive and negative components of the audio signal, respectively. Each of the power supply sections has a pair of switches which open and close alternately to transmit power pulses to opposite ends of the primary winding, and the secondary winding in turn transmit power pulses alternately through a filter component to its respective input of the amplifier section.

Abstract: A small, compact subwoofer cabinet; openings in two cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular magnet weighing approximately 225 oz affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and to the first cage; a flexible spider secured to the former and to the first cage; a mass driven driver including a mass aggregating about 2 lbs; a second flexible surround secured to the mass and to the second cage; a flexible spider attached to the second cage and to the mass; both surrounds having a thickness of about 0.1", an edgeroll having a diameter of about 1.5", and capable of standing off internal pressures of up to about 3 lbs/in.sup.

Abstract: Disclosed is an audio amplifier with a tracking power supply that uses inductive power converters to provide positive and negative amplifier operating potentials of a magnitude that exceeds the DC voltage available to power the amplifier. The tracking power supply includes both a positive-going tracking-up converter and a negative-going tracking-up converter. Each of the tracking-up converters include an inductor, a capacitor, a diode, and a pulse-width modulator. The pulse-width modulator of the positive-going tracking-up converter produces signals representative of the positive amplitude of the audio signal being amplified and the pulse-width modulator of the negative-going tracking-up converter produces signals representative of the negative amplitude of the signal being amplified.

Abstract: A small, compact subwoofer cabinet; openings in two cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular magnet weighing approximately 225 oz. affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and to the first cage; a flexible spider secured to the former and to the first cage; a mass driven driver including a mass aggregating about 2 lbs.; a second flexible surround secured to the mass and to the second cage; a flexible spider attached to the second cage and to the mass; both surrounds having a thickness of about 0.1", an edgeroll having a diameter of about 1.5", and capable of standing off internal pressures up to about 3 lbs./in.sup.

Abstract: A subwoofer including a walled cabinet defining an enclosed space of less than 1 cubic foot; axial openings formed in two opposed cabinet walls; and, two driver assemblies mounted within the cabinet on a common axis with the wall openings.

Abstract: A system for increasing the quality of the sound available from a broadcast, frequency modulated, radio frequency, stereophonic signal. Sound quality is promoted by: (1) so switching between available antennas that the signal available from the antenna receiving the incoming signal which is stronger and contains the least multipath distortion is processed into audio output signals, and (2) at least partially blending stereophonically related audio input signals into a monophonic signal if the modulation of the incoming first and second audio signals decreases below a selected threshold value and if: (a) the multipath distortion in the incoming signal reaches or exceeds a preselected threshold value, or (b) the strength of the incoming signal decreases to, or falls below, an also preselected threshold value.

Abstract: A video processor for generating an improved video display by synthesizing high frequency components of a received video signal in a manner that the frequencies of the synthesized high frequency components are greater than the upper frequency limit of the received video signal. A selected higher frequency band of the received signal modulates a continuous wave signal having a selected frequency so that the upper sideband frequency components of the modulated output are greater than the video signal upper frequency limit. The lower sideband components of the modulated output are removed and the upper sideband components are then added in phase with the original video signal to generate a composite signal having a greater bandwidth than the original received signal for generating the improved video display.

Abstract: A tuner includes circuitry for conditioning an audio signal including (i) a pilot signal canceller, (ii) a noise limiter, (iii) a notch filter, and (iv) a de-emphasizer; as well as an attenuator for RF signals. In an exemplary embodiment, an AM stereo pilot signal canceller utilizes a 25 Hz signal which is added or subtracted from the left and right channels to eliminate the pilot signal. The noise limiter includes a capacitor which is switched into the feedback circuit of an operational amplifier when the input is at a selected level. The diverting of the feedback signal to the capacitor causes the amplifier to saturate thereby removing the noise from the signal. The notch filter includes first and second band pass filters which are centered at a selected frequency, e.g. 10 kHz, for removing a 10 kHz beat note. The passed band is phase shifted so that it is 180 degrees out of phase with the original signal and then added back with the original signal to remove the selected band.

Abstract: An audio amplifier and power supply having a power transformer with power supply and control means to provide pulses of electrical energy at a substantially constant supply voltage, with the duration of the pulses being dependent upon a value that is related to the demands of the amplifier. The transformer charges a power capacitor to a substantially constant voltage to supply power for the amplifier. The frequency range of the pulses is between about 400 to 2,000 cycles per second, with a frequency being at about 1,100 cycles per second in a preferred embodiment.

Abstract: A loudspeaker diaphragm mounting system where there is a perimeter frame to which is mounted a planar flexible diaphragm having electrically conductive elements thereon. The frame has two perimeter sections which have matching perimeter grooves to receive an elongate tensioning member which presses the edge portion of the diaphragm into at least one of the grooves. By controlling the force with which the two frame sections are pushed together, tension on the diaphragm can be controlled.

Abstract: A sound recording having right and left information channels to drive right and left speakers, respectively. The right information channel has a left main stereo component having a pattern corresponding and similar to a left stereo input signal. In addition, it has a right to left compensating component having a pattern which corresponds to an inverted and delayed pattern of a right stereo input signal. In like manner, the right channel has a right main stereo component having a pattern corresponding and similar to the right stereo input signal. It also has a left to right compensating component having a pattern which corresponds to an inverted and delayed pattern of the left stereo input signal. The effect is that the main stereo components travelling to the nearest ear of a listener are not diminished substantially, while the main stereo components travelling to the further ear are diminished. The effect is a highly dimentionalized sound pattern.

Abstract: An audio amplifier operatively connected to the secondary winding of a power transformer. The primary winding of the transformer is connected through a control circuit which has switch means that is turned on and off during selected portions of half cycles of the voltage imposed upon the primary winding of the transformer. By turning the switch on and off at appropriate intervals, the proper amounts of electrical energy can be delivered to supply the power requirements for amplification, while substantially reducing problems of idling currents in the primary winding of the transformer. Thus, the transformer can be made much smaller than in power supplies of conventional amplifiers.

Abstract: The present invention comprises an amplifier circuit (2, 1100, 1500, 1600) and transformer based power supply (24, 500, 700, 1710) wherein greater efficiency is achieved by using the input signal characteristics to control various aspects of the circuit operation. The transformer primary winding (8, 500a, 700a, 1710a) is energized by a pulsed power supply (6, 502, 702, 1702) which is duty cycle modulated in response to the signal being amplified. One embodiment of the amplifier employs output transistors (Q1101, Q1103, Q1105, Q1107, Q1109, Q1111) connected to respective stepped voltage levels. Amplifier control circuitry (1126, 1130, 1138, 1140) acts in relation to the input signal amplitude to more evenly distribute the voltage drop across the interconnected transistors (Q1101, Q1103, Q1105, Q1107, Q1111), thus reducing amplifier power requirements and minimizing distortion in the amplifier output.